proxy.py

#!/usr/bin/env python3

"""
export ADDR='[("192.168.94.106", 6454), ("192.168.94.104", 6454), ("192.168.94.100", 6454), ("192.168.94.105", 6454), ("192.168.94.103", 6454), ("192.168.94.102", 6454), ("192.168.94.101", 6454)]'

# Using the proxy:
export 'ADDR=[("192.168.94.2", 8000), ("192.168.94.2", 8001),("192.168.94.2", 8002),("192.168.94.2", 8003),("192.168.94.2", 8004),("192.168.94.2", 8005),("192.168.94.2", 8006)]'


cd data/python/ohm2013/strip/
export 'ADDR=[("192.168.1.108", 6454), ("192.168.1.109", 6454)]'
./proxy.py

./fire.py 'addr=[("localhost", 8000)]'
./fire.py 'addr=[("localhost", 8001)]'

./fire.py 'addr=[("localhost", 8500)]'

"""

import socket
import signal
import sys
sys.path.append('../lib')
import select
import os
from strip import getAddr

try:
  # Python 2
  xrange
except NameError:
  # Python 3, xrange is now named range
  xrange = range

def hexdump(s):
  for b in xrange(0, len(s), 16):
    lin = [c for c in s[b : b + 16]]
    hxdat = ' '.join('%02X' % ord(c) for c in lin) # pylint: disable=consider-using-f-string
    pdat = ''.join((c if 32 <= ord(c) <= 126 else '.' )for c in lin)
    print( '  %04x: %-48s %s' % (b, hxdat, pdat) ) # pylint: disable=consider-using-f-string
  print()


class Proxy:
  localHost = "0.0.0.0"
  localPort = 8000
  broadcastPort = 8500
  addr = []
  socks = []
  socksSrc = []
  socksAddr = []

  def __init__(self, addr_ = None):
    self.addr = getAddr(addr_)

    for i, address in enumerate(self.addr):
      # Convert hostname to ip address so when can compare it with address
      # data is received from.
      self.addr[i] = (socket.gethostbyname(address[0]), address[1])

      sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
      sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
      #sock.setblocking(0)
      sock.bind((self.localHost, self.localPort + i))
      self.socks.append(sock)
      self.socksSrc.append(())
      self.socksAddr.append((self.localHost, self.localPort + i))
      print( "Channel ", self.socksAddr[i], " to ", address )

    # Add broadcast address to the lists

    # Local broadcast port
    broadcastAddr = (self.localHost, self.broadcastPort)
    # Address to broadcast to
    broadcastTo = ("", 6454)
    s = self.addr[0][0].split(".")
    s[3] = str(255)
    broadcastTo = (".".join(s), broadcastTo[1])

    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
    sock.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)
    sock.bind(broadcastAddr)
    self.socks.append(sock)
    self.socksSrc.append(())
    self.addr.append(broadcastTo)
    self.socksAddr.append(broadcastAddr)
    i = len(self.socks) - 1
    print( "Channel ", self.socksAddr[i], " to ", self.addr[i] )


  def run(self):
    while True:
      ready = select.select(self.socks, [], [], 0.5)
      index = -1
      for i in range(len(ready[0])):
        s = ready[0][i]
        for j, socks in enumerate(self.socks):
          if s == socks:
            index = j
            break
        if index >= 0:
          rdata, raddr = self.socks[index].recvfrom(5000)
          #print "received data from ", raddr, " @", self.socksAddr[index], \
          #  " to ", self.addr[index], " len=", len(rdata)
          #hexdump(rdata)

          # If address of received data is not the target address store it
          # as the source address.
          #if (len(self.socksSrc[index]) == 0) and (raddr != self.addr[index]):
          #  self.socksSrc[index] = raddr
          #  print "adding as src: ", raddr
          if raddr != self.addr[index]:
            self.socksSrc[index] = raddr
          if (raddr == self.socksSrc[index]) and (len(self.socksSrc[index]) > 0):
            #print "Send to ", self.addr[index]
            self.socks[index].sendto(rdata, self.addr[index])
          elif (raddr == self.addr[index]) and (len(self.addr[index]) > 0):
            #print "Send to ", self.socksSrc[index]
            self.socks[index].sendto(rdata, self.socksSrc[index])
          else:
            print( "Unknown address", raddr )


def signal_handler(_signal, _frame):
  os.kill(os.getpid(), signal.SIGKILL)
  sys.exit(0)

if __name__ == "__main__":
  signal.signal(signal.SIGINT, signal_handler)
  p = Proxy()
  p.run()